The spelling of jigsaw puzzle

Spell a square with a puzzle as follows:

Make a square with two triangles of the same size.

Two pieces spelling

2. Make a square with three pieces. It consists of a big triangle and two small triangles of equal size.

Three-piece spelling

3. Make a square with four pieces. It consists of a big triangle, two small triangles and a parallelogram.

Four-piece spelling

4. Make a square with seven pieces. The two large triangles on the left are placed opposite each other, and on the right is a trapezoid composed of a parallelogram, a square and two small triangles. Then use a triangle as the lower right corner and spell it into a square.

Seven-piece spelling

Tangram is an ancient traditional intellectual toy in China, which consists of seven boards. These seven boards can be combined into 1600 kinds of graphics, and more practice is very helpful to develop brain power.